Bird flu! After a couple of years, the phrase is losing its power to drive people into panic, but findings by a team of researchers including Dr. Scott Rogers of Bowling Green University suggest the threat is real in ways we hadn't realized.

His team has discovered that viruses are capable of living in the snow of Siberia for many years. Recently they identified strains of the flu from the outbreak of 1933-38 and the 1960s still alive in the ice, waiting to re-infect birds if the ice should thaw.

This suggests a cycle of re-infection that begins when birds deposit the virus in the fall, where it is soon buried in new snow. Birds return in the spring as the snow thaws, bringing them back into contact with the waiting virus. In an exceptionally warm spring, snow from previous years might melt and expose them to other forms of the virus from previous years.

While they don't discuss the effects of global warming, I have to believe that the melting of hitherto permanent snowpack at the poles could speed the return of virus forms from our past.

Recent studies on the strain that became known as the Spanish flu have shown that our modern population no longer has any immunity to it. Who knows what other strains wait under the ice?